As generally known, a robot cleaner automatically runs along the floor surface of a room and cleans the area by drawing in dust and dirt from the floor surface.
FIGS. 1 and 2 show one example of such a robot cleaner, which will be briefly described below.
FIG. 1 is a perspective view illustrating a conventional robot cleaner from which a cover is separated, and FIG. 2 is a bottom view illustrating FIG. 1 from a bottom side. The reference numeral 10 denotes a robot cleaner body, 20 is a dust suction portion, 30 is a suction opening, 40 is a sensor portion, 50 is a control portion and 60 is a battery.
As shown, there are a plurality of driving wheels 11, 12 disposed at both sides of the robot cleaner body 10 for the running of the robot cleaner. The robot cleaner body 10 is substantially a circular plate, with a substantially hemi-spherical cover attached thereto. The cover is omitted in the drawing.
The dust suction portion 20 functions to draw in dust from the floor surface with a strong suction force that the dust suction portion 20 generates at a suction port (not shown) formed in the robot cleaner body 10. The dust suction portion 20 includes a vacuum motor (not shown), and a dust collecting chamber (not shown) for collecting dust which is drawn in through the suction port by the driving of the vacuum motor.
The suction opening 30 is formed in the lower surface of the robot cleaner body 10 in fluid communication with the suction port, and within the suction opening 30, there is a rotatable brush 31 for dusting off the floor surface to be cleaned.
The sensor portion 40 is disposed along a side of the robot cleaner body 10 at predetermined intervals to externally transmit signals and receive the reflected signals. The sensor portion 40 includes an obstacle sensor (not shown) and a moving distance sensor (not shown).
The control portion 50 processes the signals received at a transceiving portion thereof, and controls the respective components, respectively. More specifically, the control portion 40 receives signals from an external control apparatus or from a remote controller, and accordingly drives the driving wheels 11, 12 and the vacuum motor of the dust suction portion 20. Further, the control portion 50 controls the operation of the robot cleaner according to the signals received from the sensor portion 40.
The robot cleaner as described above, can determine a distance to obstacles such as furniture, office machines, and walls through the sensor portion 40, and selectively drive the driving wheels 11, 12 of the robot cleaner body 10 according to that determination. When necessary, the robot cleaner can also change the direction of motion.
However, the conventional robot cleaner as described above has a problem. That is, because the suction opening 30 is fixed to the robot cleaner body 10, the distance between the floor surface to be cleaned and the suction opening 30 is subject to change in accordance with the characteristics of the floor surface to be cleaned. Accordingly, problems such as excessive contact of the suction opening 30 with the floor surface to be cleaned can occur. For example, if the robot cleaner works on a hairy area such as a carpet on the floor surface, excessive contact between the suction opening 30 with the floor surface to be cleaned may cause overload to the vacuum motor, and as a result, suction efficiency deteriorates and noise generates. Further, because the suction opening 30 is integrally formed with the robot cleaner body 10, the user of the cleaner experiences inconvenience in cleaning the suction opening 30 when contaminated.